Emergency contraception — which is just one more form of birth control — is in the headlines this week, with the Obama Administration’s decision to expand access by making it available over the counter, while at the same time still requiring that you must be 15 or older to buy it.

This is an important moment for women’s health, and it’s a good time to step back and get clarity about what emergency contraception actually is and why it matters so much.

Emergency contraception is not “the abortion pill.” Like other forms of birth control, it prevents pregnancy from happening in the first place. Specifically, emergency contraception postpones ovulation, so that sperm does not come into contact with an egg.

Pregnancy does not occur immediately after sex. It can take up to six days for an egg and a sperm to meet after having sex — a critical window of time during which pregnancy can still be prevented.

One in 10 women of reproductive age has used emergency contraception. Women use it in a variety of circumstances, including if their partner’s condom breaks, if they missed or forgot to take their regular birth control, or if they are sexually assaulted.

When a woman needs emergency contraception, time is critical. Until now, emergency contraception has been kept behind pharmacy counters because of age restrictions, which creates barriers for women of all ages because pharmacy counters usually aren’t open as long as the rest of the drugstore, lines are longer, and interactions with staff can be more complicated.

Earlier this week, the Food and Drug Administration announced that it approved plans to move emergency contraception out from behind the pharmacy counter and make it available to people ages 15 and older, with valid identification. This is an important step forward, and it will help more women of all ages prevent unintended pregnancy.

But we need to do more. The Obama Administration also announced this week that it is appealing a court decision that eliminated the age restriction entirely. We strongly disagree, and believe that the court ruling should stand. That ruling would expand access even further, and it is based on strong scientific evidence showing that age restrictions are unnecessary. Research clearly shows that emergency contraception is safe and effective at all ages, and that access to emergency contraception doesn’t increase sexual activity or high-risk behavior in young women.

May is National Teen Pregnancy Prevention Month, a reminder that we all have to do more to help prevent unintended pregnancy. An estimated 750,000 pregnancies will occur among 15- to 19-year-olds each year. While teen births have been declining since 1990, they remain higher in the U.S. than in other developed countries.

Sex education and access to birth control are effective in preventing teen pregnancy. We know what works, and now we have to make sure all women and teens have access to it. This week, we saw important progress — and we also saw how much further we have to go.